The cytoskeleton constitutes a large family of proteins that are involved in many critical processes of biology, such as chromosome and cell division, cell motility and intracellular transport (Vale and Kreis, (1993) Guidebook to the Cytoskeletal and Motor Proteins New York: Oxford University Press; Alberts et al., (1994) Molecular Biology of the Cell, 788-858). Cytoskeletal proteins are found in all cells and are involved in the pathogenesis of a large range of clinical diseases. The cytoskeleton includes a collection of polymer proteins, microtubules, actin, intermediate filaments, and septins, as well as a wide variety of proteins that bind to these polymers (polymer-interacting proteins). Some of the polymer-interacting proteins are molecular motors (myosins, kinesins, dyneins) (Goldstein (1993) Ann. Rev. Genetics 27: 319-351; Mooseker and Cheney (1995) Annu. Rev. Cell Biol. 11: 633-675) that are essential for transporting material within cells (e.g., chromosomal movement during metaphase), for muscle contraction, and for cell migration. Other groups of proteins (e.g. vinculin, talin and alpha-actinin) link different filaments, connect the cytoskeleton to the plasma membrane, control the assembly and disassembly of the cytoskeletal polymers, and moderate the organization of the polymers within cells.
Given the central role of the cytoskeleton in cell division, cell migration, inflammation, and fungal/parasitic life cycles, it is a fertile system for drug discovery. Although much is known about the molecular and structural properties of cytoskeletal components, relatively little is known about how to efficiently manipulate cytoskeletal structure and function. Such manipulation requires the discovery and development of specific compounds that can predictably and safely alter cytoskeletal structure and function. However, at present, drug targets in the cytoskeleton have been relatively untapped. Extensive work has been directed towards drugs that interact with the cytoskeletal polymers themselves (e.g., taxol and vincristine), and towards motility assays (Turner et al. (1996) Anal. Biochem. 242 (1): 20-5; Gittes et al. (1996) Biophys. J. 70 (1): 418-29; Shirakawa et al. (1995) J. Exp. Biol. 198: 1809-15; Winkelmann et al. (1995) Biophys. J. 68: 2444-53; and Winkelmann et al. (1995) Biophys. J. 68: 72S). Virtually no effort has been directed to finding drugs that target the cytoskeletal proteins that bind to the different filaments, which might be more specific targets with fewer unwanted side effects.